Pontiac Fiero 1988 Service Manual page 57

1B-12 AIR CONDITIONING
C . C . O . T . S Y S T E M A I R C O N D I T I O N I N G D I A G N O S I S
I N S U F F I C I E N T C O O L I N G " C H A R T A "
C H E C K FOR:
1. BLOWN A/C F U S E AND/OR GAGE F U S E .
2. L O O S E OR DISCONNECTED A/C WIRE CONNECTOR.
3. C H E C K BLOWER FOR FAN OPERATION.
4. ENGINE COOLING FAN OPERATION (FAN OPERATES IN ALL A/C MODES AS FOLLOWS:
A. DISCONNECT ENGINE COOLANT TEMPERATURE FAN SWITCH.
B. WITH IGNITION ON AND ENGINE NOT RUNNING, S E T A/C CONTROL TO A/C MODE.
C. ENGINE COOLING FAN SHOULD RUN.
D. R E C O N N E C T ENGINE COOLANT TEMPERATURE FAN SWITCH.
BELT PROBLEM C H E C K FOR L O O S E , MISSING OR
AMAGED DRIVE BELT
C H E C K FOR L O O S E , MISSING OR
AMAGED DRIVE BELT
BELT OK
C O M P R E S S O R S E I Z E D C H E C K FOR C O M P R E S S O R S E I Z U R E
NO SEIZURE
R E P L A C E C O M P R E S -
SOR ASSEMBLY. R E -
PLACE ORIFICE. EVA-
CUATE AND C H A R G E .
OK
CLUTCH DOES
ENGAGE OR
C Y C L E S
R E P L A C E OR TIGHTEN BELT
AS REQUIRED
AMBIENT T E M P E R A T U R E MUST B E ABOVE 10°C (50°F)
FOR FOLLOWING DIAGNOSTIC P R O C E D U R E .
C H E C K FOR C O M P R E S S O R CLUTCH ENGAGEMENT AS FOLLOWS:
1. ENGINE RUNNING (APPROX. 1000 rpm).
2. S E T A/C CONTROL TO 'NORM' AND 'HIGH' BLOWER.
3. PUT AUXILIARY FAN IN FRONT OF VEHICLE.
4. O B S E R V E CLUTCH OPERATION FOR 5 MIN.
F E E L LIQUID LINE B E F O R E EXPANSION T U B E O F F ALL THE TIME
COLD
RESTRICTION IN HIGH
SIDE OF S Y S T E M .
VISUALLY C H E C K FOR
F R O S T SPOT TO LOCATE
RESTRICTION. REPAIR.
WARM S E E CHART B
F E E L EVAPORATOR INLET AND OUTLET PIPE
INLET PIPE AND OUTLET
PIPE SAME TEMPERATURE OR
OUTLET C O L D E R THAN INLET.
INLET COLDER THAN
OUTLET PIPE.
S E E C H A R T D
EVACUATE AND C H A R G E . NO LEAK FOUND
S E E CHART C
L E A K C H E C K S Y S T E M
I
LEAK FOUND, REPAIR AS
REQUIRED, EVACUATE AND
CHARGE.
OK OK
H 2 0 0 1 2 1B
Figure 11 C.C.O.T. A/C System Insufficient Cooling Diagnostic Procedure (1 of 4)